Many roller assemblies for in-line roller skates have been introduced to this day. Typically, the roller assemblies have in common a plurality of equal size weight bearing roller wheels fastened pivotally with a roller frame such that the roller wheels are arranged linearly and glide in the same plane upon a surface. The roller frame is generally fabricated using an extrusion process, the material being a metal, such as steel or aluminum, or a composite material. The extrusion is machined so as to create two side walls that extend lengthwise of the frame and that are spaced apart transversely of the frame. The side walls are bridged by mounting brackets that are spaced lengthwise of the frame to provide for mounting of the frame to the heel and sole regions of a skating boot or shoe. It is further known to provide a transverse slot in one of these mounting brackets so that a fastening means which is used to fasten the roller frame to the boot or shoe may pass through and provide a limited degree of transverse adjustment of the roller frame on the boot or shoe at that mounting bracket. It is also known to mount the roller wheels, typically made of polyurethane, between the side walls of the frame by means of axles that fit in aligned through-holes in the side walls.
Maneuverability and stability are two important characteristics of in-line roller skates. The longer the roller wheel base of the roller assembly (e.g. the distance from front to rear roller wheels), the more stable the roller skate is but the less maneuverable it becomes. Conversely, the shorter the roller wheel base of the roller assembly, the more maneuverable the roller skate is but the less stable it becomes. The stability is due to the fact that the longer the roller wheel base is, the farther the roller wheels extend beyond the toes and heel of the skating boot or shoe having for effect to stop the user from tumbling forwards or backwards when the weight of the user is biased forward or backward, respectively. On the other hand, the longer roller wheel base hinders maneuverability by increasing the turning radius of the in-line roller skate. Conversely, the maneuverability is due to the fact that the shorter the roller wheel base is, the smaller the in-line roller skate's turning radius is. On the other hand, the shorter roller wheel base makes it easier for the user to tumble forwards or backwards when his weight is biased forward or backward, respectively.
Thus, an increase in either of the two characteristics entails a reduction in the other characteristic.